Projector

ABSTRACT

According to exemplary embodiments of the present invention, in a projection lens position, adjuster when a part of a dial exposed from an exterior case is rotated downward, a gear is rotated in an R 2  direction. A Y-slider is then moved downward (in a Y 3  direction). Accordingly, a Y-table is moved downward, as is a projection lens. When the part of the dial exposed from the exterior case is rotated upward, the projection lens is moved upward. When a part of a dial exposed form the exterior case is rotated leftward as seen from a rear side of a projector, the projection lens is moved leftward. In contrast, when the dial is rotated rightward, the projection lens is moved rightward. Provided around the projection lens are a first light shield for closing a gap between an opening of a front case and a periphery of the projection lens, and a second light shield for closing a gap between the projection lens and a hole of a base of the projection lens position adjuster A shield body of the first light shield includes a ring-shaped elastic member disposed to extend between a ring and the projection lens, and a pair of attachments extending from the elastic member outward.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a projector.

2. Description of Related Art

The related art includes projectors that are used for presentations atconferences, academic societies and exhibitions. Each of such projectorsmodulates and combines a light beam irradiated by a light source inaccordance with image information and projects the light beam on ascreen by a projection optical system in an enlarged manner.

In the above projector, there may be an occasion of projecting upwardwith the projector fixed at a lower level, or that of projectingdownward with the projector fixed at a higher level. Related artdocument JP10-171044A, 3 to 4 pages, FIG. 2, discloses a projector,which is provided with a projection optical system position adjuster atan optical system such as an optical modulator etc. The projectionoptical system position adjuster moves a projection optical system in adirection orthogonal to a light-irradiating direction. The projectionoptical system position adjuster rotates a knob (rotary knob) left andright to drive as screwing the knob so as to move the projection opticalsystem up and down.

However, in such a projection optical system position adjuster, since arotary direction of the knob and a moving direction of the projectionoptical system are not correspondent, it is difficult to figure outwhether the projection optical system is moved up or down, which is afirst problem.

Further, in the projector equipped with the projection optical systemposition adjuster, an elongated opening through which a projection lensis exposed is formed at the projection optical system position adjusterand the casing where the projection lens is housed, so that theprojection lens is moved along these elongated openings. In suchprojector, when the projection optical system is moved, a gap isgenerated between the projection optical system and the opening formedat the casing, thus the dusts etc. possibly being invaded from the gap.Additionally, the generated gap disfigures the projector. To close thegap, there is provided one or two shield plates which moves along withthe projection lens on an inner side of the casing.

However, when the one or two shield plates follows the projection lens,the dimension of the casing along the moving direction of the projectionlens must be long enough to secure a range where the shield plates moveinside the casing. Accordingly, the length of the casing in the movingdirection of the projection lens might be increased, thus increasing thesize of the casing, which is a second problem.

Furthermore, when the two shield plates are used, a gap is generated ata part where the two shield plates are layered, and a light may leakfrom the gap, which is a third problem.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a projectorhaving a projection optical system position adjuster that enables a userto easily recognize a moving direction of a projection optical system.

Exemplary embodiments of the present invention provide a projector thatcan securely reduce or prevent a light beam from leaking, and alsoreduce or prevent increase of a size of a casing thereof.

A projector according to an exemplary aspect of the present inventionthat forms an optical image by modulating a light beam irradiated by alight source in accordance with image information and projects theoptical image by a projection optical system in an enlarged manner,includes: a projection optical system position adjuster that moves theprojection optical system on a plane orthogonal to a light-projectingdirection and adjusts a position of a projection area of the projectionoptical system; and a casing where the projection optical systemposition adjuster and the projection optical system are housed, in whichthe projection optical system position adjuster has a first dial and asecond dial exposed from the casing when the first dial and the seconddial are housed in the casing for adjusting a position of the projectionoptical system, in which a moving direction of the projection opticalsystem according to a rotation of the first dial is approximatelyorthogonal to a moving direction of the projection optical systemaccording to a rotation of the second dial, and in which rotarydirections of the first dial and the second dial at parts exposed fromthe casing are approximately correspondent to the directions to whichthe projection optical system is moved.

With this arrangement, since each rotary direction of the first dial andthe second dial at the parts exposed from the casing for adjusting theposition of the projection optical system is approximately consistentwith the moving direction of the projection optical system, a user caneasily recognize the moving direction of the projection optical system.Accordingly, a user may smoothly adjust the position of the projectionoptical system.

Especially, in such case that the projection optical system is movedtoward two directions approximately orthogonal to each other, if therotary direction of the dial is not consistent with the moving directionof the projection optical system, the user is difficult to recognize themoving direction of the projection optical system, thus likely confusingthe user. However, in this configuration, each rotary direction of thefirst dial and the second dial at the parts exposed from the casing isapproximately consistent with the moving direction of the projectionoptical system, so that the user can easily recognize the movingdirection of the projection optical system, thus enhancing or improvinga usability.

Preferably, in the above projector, the projection optical systemposition adjuster has a base fixed on the casing and provided with ahole where the projection optical system is moved, a mount slidablyprovided on the base with the projection optical system attachedthereto, a first transmitter that transmits the rotation of the firstdial to the mount to linearly drive the mount, and a second transmitterthat transmits the rotation of the second dial to the mount to linearlydrive the mount.

With this arrangement, when the first dial and the second dial arerotated, each rotation is transmitted to the mount by the firsttransmitter and the second transmitter, so that the mount is linearlydriven. Since the projection optical system is attached to the mount,the projection lens is also linearly driven, thus adjusting the positionof the projection optical system.

Preferably, in the above projector, the first and the secondtransmitters respectively have a slider fixed on the mount to slidetogether with the mount, and a gear that rotates along with the rotationof the first dial or the second dial and meshes with the slider.

Since the gear meshes with the slider, the slider is driven as the gearis rotated due to the rotation of the dial. The mount is then movedalong with the drive of the slider, accordingly adjusting the positionof the projection optical system.

In such configuration, since the rotation of the dial is converted intothe linear drive by way of the gear and the slider, the drive structureis simple and the structure of the projection optical system positionadjuster would not be complicated.

Preferably, in the above projector, the projection optical systemposition adjuster includes a recognizer for recognizing a referenceposition of the projection optical system, and the recognizer changeseach rotation torque of the first dial and the second dial.

With this arrangement, since the recognizer for recognizing thereference position of the projection optical system is provided, whichchanges the rotation torque of the dial, in other words, which changesthe force causing the dial to rotate, the user can easily recognize theposition of the projection optical system while rotating the dial.Therefore, the usability can be enhanced improved.

Preferably, in the above projector, the projection optical systemposition adjuster has a base fixed on the casing and provided with ahole where the projection optical system is moved, a mount slidablyprovided on the base with the projection optical system attachedthereto, a first transmitter that transmits a rotation of the first dialto the mount to linearly drive the mount, and a second transmitter thattransmits a rotation of the second dial to the mount to linearly drivethe mount, the recognizer includes the transmitter having a recess or aprotrusion, and a biasing member having a protrusion or a recess andabutting on the transmitter by being biased toward the transmitter, andeach rotation torque of the first dial and the second dial is changedwhen the recess engages with the protrusion.

When the protrusion is formed at the transmitter, the biasing memberhaving the recess is used. On the other hand, when the recess is formedat the transmitter, the biasing member having the protrusion is used.

For example, when the recess is formed at the transmitter whereas theprotrusion is formed at the biasing member, the protrusion abuts on thetransmitter by being biased toward the transmitter until the projectionoptical system reaches the reference position. Since the transmitter isdriven along with the rotation of the dial, a constant friction isgenerated between the protrusion and the transmitter, which causes arotation torque of the dial. When the projection optical system reachesthe reference position, the recess engages with the protrusion, thefriction is then reduced and the rotation torque of the dial is alsoreduced. Thus, the reference position of the projection lens can easilybe recognized by the user.

The same advantages can be obtained when the protrusion is formed at thetransmitter whereas the recess is formed at the biasing member instead.

Since the transmitter is directly connected to the dial, the change ofthe friction when the recess engages with the protrusion can directly betransmitted to the dial. Accordingly, the change of the rotation torqueof the dial can securely be recognized by the user, thus furtherenhancing or improving the usability.

Further, since the recognizer applies the configuration where the recessengages with the protrusion, the structure of the recognizer would notbe complicated.

Preferably, in the above projector, the projection optical systemposition adjuster has a base fixed on the casing and provided with ahole where the projection optical system is moved and a mount slidablyprovided on the base with the projection optical system attachedthereto, the first dial and the second dial respectively include a dialbody exposed from the casing and a shaft provided at the dial and fixedon the base, the recognizer includes the shaft having a recess or aprotrusion, and a biasing member having a protrusion or a recess andabutting on the shaft by being biased toward the shaft, and eachrotation torque of the first dial and the second dial is changed whenthe recess engages with the protrusion.

When the recess is formed at the shaft, the biasing member having theprotrusion is used, and when the protrusion is formed at the shaft, thebiasing member having the recess is used.

With this arrangement, for example, when the recess is formed at theshaft whereas the protrusion is formed at the biasing member, theprotrusion abuts on the shaft by being biased toward the shaft until theprojection optical system reaches the reference position. According tothe rotation of the shaft, the friction is created between it and theprotrusion, which causes a rotation torque of the dial. When theprojection optical system reaches the reference position, the recessengages with the protrusion, the friction is then reduced and therotation torque of the dial is also reduced. Thus, the referenceposition of the projection lens can easily be recognized by the user.

The same advantages can be obtained when the protrusion is formed at theshaft whereas the recess is formed at the biasing member instead.

With this arrangement, since the recess or the protrusion is formed onthe dial itself, the user can further securely recognize the change ofthe friction when the recess engages with the protrusion as the changeof the rotation torque.

Further, since the recognizer applies the configuration where the recessengages with the protrusion, the structure of the recognizer would notbe complicated.

Preferably, in the above projector, the reference position of theprojection optical system is approximately at the mid position in themoving direction of the projection optical system.

The reference position is approximately the mid position (centerposition) in the moving direction of the projection optical system, sothat the user can easily recognize the center position. For instance,the center position is effective when the optical axis of the projectionoptical system is approximately consistent with the center of the imageprojected on the screen.

A projector according to another exemplary aspect of the presentinvention includes: a light source; an optical modulator that forms anoptical image by modulating a light beam irradiated by the light sourcein accordance with image information; a device body having a projectionoptical system that projects the optical image formed by the opticalmodulator in an enlarged manner; and a casing where the device body ishoused, in which the projection optical system is provided with aprojection optical system position adjuster that adjusts a position of aprojection area, in which the casing has an opening through which theprojection optical system is exposed and moved by the projection opticalsystem position adjuster, in which a light shield for closing a gapbetween the projection optical system and the opening is disposed insidethe casing, and in which the light shield includes a ring held at aperiphery of the projection optical system in a loosely fitted manner,and an elastic member disposed to extend between the ring and aperipheral edge of the opening of the casing.

With this arrangement, since the light shield has the elastic memberdisposed to extend between the ring attached to the projection opticalsystem and the peripheral edge of the opening of the casing, the gapbetween the projection optical system and the opening can be closed.Since the elastic member is attached to the ring held by the projectionoptical system, when the position of the projection optical system isadjusted, the elastic member is stretched and compressed to follow themovement of the projection optical system. Accordingly, even when theposition of the projection optical system is adjusted, the gap betweenthe projection optical system and the opening can securely be closed,thus preventing the light leakage.

Further, since the gap between the projection optical system and theopening can securely be closed, the invasion of the dusts from the gapcan also be reduced or prevented.

Further, in the light shield according to the above exemplary aspect ofthe present invention, since the elastic member is stretched andcompressed to follow the movement of the projection optical system, butthe shield plate does not follow it unlike the conventional manner, thedimension of the casing along the moving direction of the projectionoptical system is not required to be elongated in order to secure therange where the light shield moves inside the casing, thus reducing orpreventing the casing from growing in the size.

Since the ring is held at the periphery of the projection optical systemin a loosely fitted manner, the ring would not be rotated even when theprojection optical system is rotated during the focus adjustment etc.Since the elastic member is fixed on such ring, the elastic member canbe reduced or prevented from twisting etc. caused by an external forceapplied to the elastic member along with the rotation of the projectionoptical system.

Preferably, in the above projector, the projection optical systemposition adjuster has a base having a hole through which the projectionoptical system is inserted and moved, and a second light shieldincluding an elastic member disposed to extend between the periphery ofthe projection optical system and a peripheral edge of a hole of thebase.

With this arrangement, since the projector includes the second lightshield which has the elastic member disposed to extend between theperiphery of the projection optical system and the peripheral edge ofthe hole of the base of the projection optical system position adjuster,the light leakage from the gap between the projection optical systemposition adjuster and the projection optical system can be reduced orprevented.

Since the second light shield has the elastic member as is theabove-described light shield, the elastic member is stretched andcompressed when the position of the projection optical system isadjusted to follow the movement of the projection optical system.Accordingly, when the position of the projection optical system isadjusted, the gap between the projection optical system positionadjuster and the projection optical system can securely be closed.

Further, since the gap between the projection optical system and theprojection optical system position adjuster can securely be closed, theinvasion of the dusts from the gap can also be reduced or prevented.

Since there are provided the two light shields of the above-describedlight shield and the second light shield, the light leakage and theinvasion of the dusts can securely be reduced or prevented.

Preferably, in the above projector, the elastic member includes adeformable part disposed between the ring and the peripheral edge of theopening of the casing, or between the periphery of the projectionoptical system and the peripheral edge of the hole of the base, andattachments provided on both ends of the deformable part to be attachedto the ring and the peripheral edge of the opening of the casing, or tobe attached to the periphery of the projection optical system and theperipheral edge of the hole of the base, and the deformable part isformed thinner than the attachment.

With this arrangement, the deformable part that deforms along with theposition adjustment of the projection optical system is formed thinner,the deformable part can flexibly be deformed along with the positionadjustment of the projection optical system. Accordingly, the positionadjustment of the projection optical system would not be difficultbecause of providing the light shield, but the position thereof cansmoothly be adjusted with the light shield applied.

Further, the attachment is formed thicker than the deformable part so asto be fixed at the ring and the peripheral edge of the opening of thecasing, or at the periphery of the projection lens and the peripheraledge of the hole of the base tightly.

Preferably, in the above projector, the light shield includes a fixingplate for fixing the elastic member at the peripheral edge of theopening of the casing, and the elastic member is sandwiched between thefixing plate and the peripheral edge of the opening of the casing.

With this arrangement, since the elastic member of the light shield issandwiched by the fixing plate and the casing, the elastic member cansecurely be attached to the peripheral edge of the opening of thecasing.

Preferably, the above projector further includes: a projection opticalsystem position adjuster that moves the projection optical system on aplane orthogonal to a light-projecting direction and adjusts a positionof a projection area, in which the projection optical system positionadjuster has a dial exposed from the casing when the dial is housed inthe casing, in which a position of the projection optical system isadjusted according to a rotation of the dial, and in which a rotarydirection of the dial at the part exposed from the casing isapproximately consistent with a direction to which the projectionoptical system is moved.

With this arrangement, since the rotary direction of the dial at thepart exposed from the casing for adjusting the position of theprojection optical system is approximately consistent with the movingdirection of the projection optical system, the user can easilyrecognize the moving direction of the projection optical system.Accordingly, the user may smoothly adjust the position of the projectionoptical system.

Preferably, in the above projector, in which the projection opticalsystem position adjuster has a base fixed on the casing and providedwith a hole where the projection optical system is moved, a mountslidably provided on the base with the projection optical systemattached thereto, and a transmitter that transmits a rotation of thedial to the mount to linearly drive the mount.

With this arrangement, when the dial is rotated, the rotation istransmitted to the mount by the transmitter, and the mount is thenlinearly driven. Since the projection optical system is attached to themount, the projection lens is also linearly driven, thus adjusting theposition of the projection optical system.

Preferably, in the above projector, the transmitter has a slider fixedon the mount to slide together with the mount, and a gear that rotatesalong with the rotation of the dial and meshes with the slider.

Since the gear meshes with the slider, the slider is driven as the gearis rotated due to the rotation of the dial. The mount is then movedalong with the drive of the slider, accordingly adjusting the positionof the projection optical system.

In such configuration, since the rotation of the dial is converted intothe linear drive by way of the gear and the slider, the drive structureis simple and the structure of the projection optical system positionadjuster would not be complicated.

Preferably, in the above projector, the projection optical systemposition adjuster includes a recognizer for recognizing a referenceposition of the projection optical system, and the recognizer changes arotation torque of the dial.

With this arrangement, since the recognizer for recognizing thereference position of the projection optical system is provided, whichchanges the rotation torque of the dial, in other words, which changesthe force causing the dial to rotate, the user can easily recognize theposition of the projection optical system while rotating the dial.Therefore, the usability can be enhanced or improved.

Preferably, in the above projector, the projection optical systemposition adjuster has a base fixed on the casing and provided with ahole where the projection optical system is moved, a mount slidablyprovided on the base with the projection optical system attachedthereto, and a transmitter that transmits a rotation of the dial to themount to linearly drive the mount, the recognizer has the transmitterhaving a recess or a protrusion, and a biasing member having aprotrusion or a recess and abutting on the transmitter by being biasedtoward the transmitter, and the rotation torque of the dial is changedwhen the recess engages with the protrusion.

When the protrusion is formed at the transmitter, the biasing memberhaving the recess is used. On the other hand, when the recess is formedat the transmitter, the biasing member having the protrusion is used.

For example, when the recess is formed at the transmitter whereas theprotrusion is formed at the biasing member, the protrusion abuts on thetransmitter by being biased toward the transmitter until the projectionoptical system reaches the reference position. Since the transmitter isdriven along with the rotation of the dial, a constant friction isgenerated between the protrusion and the transmitter, which causes arotation torque of the dial. When the projection optical system reachesthe reference position, the recess engages with the protrusion, thefriction is then reduced and the rotation torque of the dial is alsoreduced. Thus, the reference position of the projection lens can easilybe recognized by the user.

The same advantages can be obtained when the protrusion is formed at thetransmitter whereas the recess is formed at the biasing member instead.

Since the transmitter is directly connected to the dial, the change ofthe friction when the recess engages with the protrusion can directly betransmitted to the dial. Accordingly, the change of the rotation torqueof the dial can securely be recognized by the user, thus furtherenhancing or improving the usability.

Further, since the recognizer applies the configuration where the recessengages with the protrusion, the structure of the recognizer would notbe complicated.

Preferably, in the above projector, the projection optical systemposition adjuster has a base fixed on the casing and provided with ahole where the projection optical system is moved and a mount slidablyprovided on the base with the projection optical system attachedthereto, the dial includes a dial body exposed from the casing and ashaft provided at the dial and fixed on the base, the recognizer has theshaft having a recess or a protrusion, and a biasing member having aprotrusion or a recess and abutting on the shaft by being biased towardthe shaft, and the rotation torque of the dial is changed when therecess engages with the protrusion.

When the recess is formed at the shaft, the biasing member having theprotrusion is used, and when the protrusion is formed at the shaft, thebiasing member having the recess is used.

With this arrangement, for example, when the recess is formed at theshaft whereas the protrusion is formed at the biasing member, theprotrusion abuts on the shaft by being biased toward the shaft until theprojection optical system reaches the reference position. According tothe rotation of the shaft, the friction is created between it and theprotrusion, which causes a rotation torque of the dial. When theprojection optical system reaches the reference position, the recessengages with the protrusion, the friction is then reduced and therotation torque of the dial is also reduced. Thus, the referenceposition of the projection lens can easily be recognized by the user.

The same advantages can be obtained when the protrusion is formed at theshaft whereas the recess is formed at the biasing member instead.

With this arrangement, since the recess or the protrusion is formed onthe dial itself, the user can further securely recognize the change ofthe friction when the recess engages with the protrusion as the changeof the rotation torque.

Further, since the recognizer applies the configuration where the recessengages with the protrusion, the structure of the recognizer would notbe complicated.

Preferably, in the above projector, the reference position of theprojection optical system is approximately at the mid position in themoving direction of the projection optical system.

The reference position is approximately the mid position (centerposition) in the moving direction of the projection optical system, sothat the user can easily recognize the center position. For instance,the center position is effective when the optical axis of the projectionoptical system is approximately consistent with the center of the imageprojected on the screen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view showing an upper front side of aprojector according to a first exemplary embodiment of the presentinvention;

FIG. 2 is a schematic perspective view showing a lower front side of theprojector of the aforesaid exemplary embodiment;

FIG. 3 is a schematic perspective view showing an upper rear side of theprojector of the aforesaid exemplary embodiment;

FIG. 4 is a schematic perspective view showing an upper side of a lowercase and a front case of the projector of the aforesaid exemplaryembodiment;

FIG. 5 is a schematic perspective view showing an interior structure ofthe projector of the aforesaid exemplary embodiment;

FIG. 6 is a schematic illustration showing an optical system of anoptical unit of the aforesaid exemplary embodiment;

FIG. 7 is a schematic perspective view showing a light guide of theaforesaid exemplary embodiment;

FIG. 8 is a schematic perspective view showing a projection lensposition adjuster of the aforesaid exemplary embodiment;

FIG. 9 is a schematic illustration showing a position of an imageprojected by a projection lens;

FIG. 10 is a schematic perspective view showing the projection lensposition adjuster;

FIG. 11 is a schematic perspective view showing a primary portion of theprojection lens position adjuster;

FIG. 12 is a schematic perspective view showing the projection lensposition adjuster;

FIG. 13 is a schematic perspective view showing the projection lens withfirst and second light shields attached;

FIG. 14 is a schematic perspective view showing the first light shield;

FIG. 15 is a schematic cross section of the projection lens, the firstlight shield and the second light shield;

FIG. 16 is a schematic perspective view showing the second light shield;

FIG. 17 is a schematic perspective view showing a primary portion of aprojection lens position adjuster according to a second exemplaryembodiment of the present invention; and

FIG. 18 is a schematic illustration showing a relationship between anumber of rotation of a dial and a rotation torque of the secondexemplary embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be described belowwith reference to the attached drawings.

[First Exemplary Embodiment]

(1) Exterior Arrangement

FIG. 1 is a schematic perspective view showing an upper front side of aprojector 1 according to the present exemplary embodiment. FIG. 2 is aschematic perspective view showing a lower front side of the projector1. FIG. 3 is a schematic perspective view showing an upper rear side ofthe projector 1. FIG. 4 is a schematic perspective view showing a partof an exterior case 2 of the projector 1.

The projector 1 modulates a light beam irradiated by a light source inaccordance with image information and projects the light beam on aprojection surface such as a screen in an enlarged manner. As shown inFIGS. 1 to 3, the projector 1 has an approximately rectangularparallelepiped exterior case 2 and a projection lens 3 exposed from theexterior case 2.

The projection lens 3 serves as a projection optical system thatprojects in an enlarged manner an optical image modulated by a liquidcrystal panel, which is a below-described optical modulator. Theprojection lens 3 is configured as a lens set including a plurality oflenses housed in a lens barrel.

The exterior case 2 is an approximately planarly-viewed rectangularcasing made of synthetic resin, which houses a device body including anoptical unit (described below) of the projector 1. The exterior case 2has an upper case 21 covering an upper section of the device body, alower case 22 covering a lower section of the device body, a front case23 covering a front section of the device body, a side case 24 coveringa part of a lateral section of the device body and a rear case 25 (FIG.3) covering a rear section of the device body.

Note that, each comer of an upper side, a front side, a lateral side, abottom side and a rear side of the exterior case 2 is curved.

The upper case 21 has an approximately planarly-viewed rectangular upperside 21A covering the upper section of the device body, a lateral side21B extending substantially vertically downward from a longitudinal edgeof the upper side 21 A, a lateral side 21 C extending substantiallyvertically downward from the other longitudinal edge of the upper side21A, and a rear side 21D (see FIG. 3) extending substantially verticallydownward from a rear edge of the upper side 21A.

As shown in FIG. 1 or 3, an operation panel 26 for actuating andadjusting the projector 1 is provided approximately at the rear centerof the upper side 21A as extending horizontally. Pushing an operationbutton 261 of the operation panel 26 causes contact with a tactileswitch installed on a circuit board (not shown) disposed inside theoperation panel 26 to allow a desired operation. Additionally, an LED(not shown here) is mounted on the circuit board so that the LED emits alight in response to the desired operation.

A decorative board 262 is provided on the operation panel 26 so that theoperation button 261 is surrounded by the decorative board 262. Thelight emitted by the LED is diffused via the decorative board 262.

Two dials 311 and 321 (a first dial 311 and a second dial 321) of aprojection lens position adjuster 30 (see FIG. 4) to vertically andhorizontally move the projection lens 3 to adjust the position of theprojection lens 3 are exposed from the front side of the upper side 21A(right side in FIG. 1). When the dial 311 disposed at the left side inFIG. 1 out of the two dials 311 and 321 is moved in a Y1 direction(downward), the projection lens 3 is moved in a Y3 direction (downward).In contrast, when the dial 311 is moved in a Y2 direction (upward), theprojection lens 3 is moved in a Y4 direction (upward).

When the dial 321 disposed at the right side in FIG. 1 is moved in an X1direction (rightward as seen from the rear side of the projector 1), theprojection lens 3 is moved in an X3 direction (rightward). In contrast,when the dial 321 is moved in an X2 direction (leftward as seen from therear side of the projector 1), the projection lens 3 is moved in an X4direction (leftward). Namely, the moving directions of the projectionlens 3 by way of the dials 311 and 321 are substantially orthogonal toeach other.

Though not shown, a rib is vertically arranged on an inner side of theupper side 21A to surround a periphery of the projection lens 3.

A cutting portion 21C1 is formed at the lateral side 21C, through whicha louver 71 having a plurality of vanes 711 is exposed.

Referring to FIG. 3, a cutting portion 21D1 that engages with the rearcase 25 is formed on the rear side 21D.

As shown in FIGS. 1 to 4, the lower case 22 has a bottom side 22A,lateral sides 22B and 22C, a rear side 22D and a front side 22E.

As shown in FIG. 2, the bottom side 22A is an approximatelyplanarly-viewed rectangle with a fixed leg 221A1 provided on the bottomside 22A approximately at the center of the rear side of the projector 1and an adjustment leg 27 provided thereon at both ends in a longitudinaldirection of the front side.

The adjustment leg 27 has a shaft member 271 (see FIG. 5)advanceably/retractably projecting from the bottom side 22A in anout-plane direction, so that the vertical and horizontal inclination ofthe projector 1 can be adjusted while the projector 1 projecting animage.

Further, an opening 22A3 communicating with the inside of the exteriorcase 2 is formed at the bottom side 22A.

The opening 22A3 is an intake for drawing in cooling air from theoutside of the exterior case 2. A cover 22A5 with a plurality ofopenings formed is attached to the opening 22A3.

As shown in FIG. 4, a rib 22A6 is vertically arranged on the bottom side22A to surround the periphery of the projection lens 3.

The lateral side 22B is vertically arranged on a longitudinal edge ofthe bottom side 22A to compose the lateral side of the exterior case 2by engaging with the lateral side 21B of the upper case 21 as shown inFIG. 2.

As shown in FIG. 2, a recess 22B1 is dented toward the upper case 21 toserve as a suspender for suspending the projector 1.

As shown in FIG. 1, the lateral side 22C is vertically arranged at theother longitudinal edge of the front side of the bottom side 22A tocompose a part of the lateral side of the exterior case 2 by engagingwith the lateral side 21 C of the upper case 21. A cutting portion 22C1is formed at the lateral side 22C by largely cutting out an upper edgethereof, so that the louver 71 is exposed through the cutting portion22C1. That is, an opening with the louver 71 exposed through is formedby the cutting portion 21C1 of the lateral side 21C and the cuttingportion 22C1 of the lateral side 22C. Air having cooled the inside ofthe projector 1 is discharged from the opening.

As shown in FIG. 3, the rear side 22D is vertically arranged on an edgeof a shorter side of the bottom side 22A. A cutting portion 22D1 thatengages with the rear case 25 is formed on the rear side 22D. Namely, inthe present exemplary embodiment, the rear sides 21D, 22D and the rearcase 25 compose the rear side of the exterior case 2.

A rectangular opening 22D2 is formed at the rear side 22D, and an inletconnector 22D3 is exposed through the opening 22D2. The inlet connector22D3 is a terminal to supply the electric power supplied from theoutside power source to the projector 1, the inlet connector 22D3 beingconnected to a below-described power source unit electrically.

Referring to FIG. 1 again, the front side 22E is vertically arranged onthe other edge of the sorter side of the bottom side 22A. The front side22E engages with the front case 23 to compose the front side of theexterior case 2.

As shown in FIGS. 1 and 2, the approximately ellipsoidal front case 23has an opening 231 through which the projection lens 3 is exposed on theside of the longitudinal edge (right side in FIG. 1). Though not shown,a first light shield for closing a gap between the opening 231 and theperiphery of the projection lens 3, and a second light shield 12 (seeFIG. 4) for closing a gap between the projection lens 3 and theprojection lens position adjuster 30 are attached to the projection lens3 exposed through the opening 231.

A remote controller sensor window 232 is formed approximately at thecenter of the front case 23. A remote controller module (not shown) forreceiving an operation signal from a remote controller (not shown) isdisposed inside the remote controller sensor window 232.

An activation switch and an adjustment switch etc. similar to the oneprovided on the operation panel 26 are provided on the remotecontroller. When the remote controller is operated, an infrared signalcorresponding to the operation is output from the remote controller tobe received by a receiver via the remote controller sensor window 232,so that the infrared signal is processed by the below-described controlboard.

As shown in FIG. 4, a rib 234 is vertically arranged at the inner sideof the front case 23 to surround the periphery of the projection lens 3.The rib 234, the rib 22A6 of the bottom side 22A of the lower case 22,and the rib of the upper side 21A of the upper case 21 compose a lenshouse to surround the projection lens 3.

As shown in FIGS. 1 and 3, the side case 24 has an upper side 24A and alateral side 24C extending substantially vertically downward from theupper side 24A. The upper side 24A composes the upper side of theexterior case 2 by engaging with the upper side 21A of the upper case21.

The lateral side 24C engages with the lateral side 21C of the upper case21 and the lateral side 22C of the lower case 22.

As shown in FIG. 3, the rear case 25 is fixed by fitting into an openingformed by the cutting portion 2 1D1 of the rear side 21D of the uppercase 21 and the cutting portion 22D1 of the rear side 22D of the lowercase 22.

The rear case 25 is a planarly-viewed rectangle. A remote controllersensor window 232 similar to the one of the front case 23 is formedaround the longitudinal edge of the rear case 25.

A dent 251 dented toward the inside of the exterior case 2 is formed onthe rear case 25, and a plurality of connector terminals 252 are exposedfrom the dent 251.

The connector terminals 252 input an image signal and a sound signaletc. output from external electric equipments, and are connected to aninterface board located inside the rear case 25.

Incidentally, the interface board is electrically connected to thebelow-described control board and the signal processed by the interfaceboard is output to the control board.

(2) Internal Arrangement

FIG. 5 is a schematic showing the internal arrangement of the projector1. More specifically, FIG. 5 only shows the lower case 22 of theexterior case 2, with the upper case 21, the front case 23, the sidecase 24 and the rear case 25 removed.

The device body 8 of the projector 1 is housed inside the exterior case2, the device body 8 including the optical unit 4 horizontally extendingalong the longitudinal direction of the exterior case 2, the controlboard 5 disposed at an upper part of the optical unit 4, and the powersource unit 6.

(2-1) Structure of Optical Unit 4

The optical unit 4 modulates a light beam irradiated by a light sourcein accordance with image information to form an optical image, and formsa projected image on a screen through the projection lens 3. As shown inFIG. 6, the optical unit 4 includes functionally independent componentsof an integrator illuminating optical system 41, a color-separatingoptical system 42, a relay optical system 43, an optical device 44integrating an optical modulator and a color-combining optical device,and an approximately rectangular parallelepiped inner case 45 (see FIG.7) in which the optical components 41, 42, 43 and 44 are housed andarranged.

The integrator illumination optical system 41 is an optical system forequalizing the illuminance of the light beam irradiated by the lightsource on a plane orthogonal to the illumination optical axis. Theintegrator illuminating optical system 41 has a light source device 411,a first lens array 412, a second lens array 413, a polarizationconverter 414 and a superposing lens 415.

The light source device 411 has a light source lamp 411A (a radial lightsource), a reflector 411B, and an anti-explosion glass 411C covering alight-irradiation side of the reflector 411B. The radial light beamirradiated by the light source lamp 411A is reflected by the reflector411B to be an approximately parallel light beam and is irradiated towardthe outside. In the present exemplary embodiment, a high-pressuremercury lamp is used as the light source lamp 411A and a parabolicmirror is used as the reflector 411B. Incidentally, the light sourcelamp 411A may not be a high-pressure mercury lamp but may be a metalhalide lamp or a halogen lamp. Further, though a parabolic mirror isused as the reflector 411B, a parallelizing concave lens disposed on theirradiation-side of a reflector of an ellipsoidal mirror mayalternatively be used.

The first lens array 412 has small lenses arranged in a matrix, thelenses having substantially rectangular profile seen in the illuminationoptical axis direction. The respective lenses separates the light beamirradiated by the light source lamp 411A into sub-beams and emits thesub-beams in the illumination optical axis direction.

The second lens array 413 is arranged approximately in the same manneras the first lens array 412, which includes small lenses arranged in amatrix. The second lens array 413 together with the superposing lens 415superposes the image of the respective small lenses of the first lensarray 412 onto the below-described liquid crystal panels 441R, 441G and441B of the optical device 44.

The polarization converter 414 converts the light from the second lensarray 413 into substantially uniform polarized light, thereby enhancingthe light utilization efficiency of the optical device 44.

Specifically, the respective sub-beams converted into substantiallyuniform polarized light by the polarization converter 414 issubstantially superposed on the below-described liquid crystal panels441R, 441G and 441B of the optical device 44 by the superposing lens415. Since only one-type of polarized light can be used in a projectorusing the liquid crystal panels 441R, 441G and 441B that modulates apolarized light, approximately half of the light beam from the lightsource lamp 411A emitting random polarized light cannot be used.Accordingly, with the use of the polarization converter 414, the lightbeam irradiated by the light source lamp 411A is converted intosubstantially uniform polarized light to enhance the light utilizationefficiency of the optical device 44. Incidentally, such polarizationconverter 414 is disclosed in, for instance, related art documentJP08-304739A.

The color-separating optical system 42 has two dichroic mirrors 421 and422, and a reflection mirror 423. The plurality of sub-beams irradiatedby the integrator illuminating optical system 41 are separated intothree color lights of red (R), green (G) and blue (B) by the twodichroic mirrors 421 and 422.

The relay optical system 43 has an incident-side lens 431, a pair ofrelay lenses 433, and reflection mirrors 432 and 435. The relay opticalsystem 43 guides the color light (blue light) separated by thecolor-separating optical system 42 toward the below-described liquidcrystal panel 441B of the optical device 44.

At this time, the dichroic mirror 421 of the color-separating opticalsystem 42 transmits the green light component and blue light componentof the light beam irradiated by the integrator illuminating opticalsystem 41 and reflects the red light component. The red light reflectedby the dichroic mirror 421 is reflected by the reflection mirror 423,which reaches the liquid crystal panel 441R for red color through afield lens 419. The field lens 419 converts the respective sub-beamsirradiated by the second lens array 413 into a light beam parallel tothe central axis (main beam) thereof. The field lenses 419 provided onthe light-incident side of the other liquid crystal panels 441G and 441Bfunction in the same manner.

In the blue and green lights transmitted through the dichroic mirror421, the green light is reflected by the dichroic mirror 422, whichreaches the liquid crystal panel 441G for green light through the fieldlens 419. On the other hand, the blue light passes through the dichroicmirror 422, which passes through the relay optical system 43 to reachthe liquid crystal panel 441B for blue light through the field lens 419.

Note that, the relay optical system 43 is used for the blue light inorder to avoid deterioration in the light utilization efficiency onaccount of light dispersion and the like caused by the longer length ofthe optical path of the blue light than the optical path of the othercolor light. In other words, the relay optical system 43 is used fordirectly transmitting the sub-beams incident on the incident-side lens431 to the field lens 419. Incidentally, though the blue light of thethree color lights passes through the relay optical system 43, the redlight, for instance, may alternatively pass through the relay opticalsystem 43.

The optical device 44 modulates the incident light beam in accordancewith image information to form a color image. The optical device 44 hasthree incident-side polarization plates 442 on which the respectivecolor lights separated by the color-separating optical system 42 areincident, the liquid crystal panels 441 (441R, 441G and 441B) as opticalmodulators and irradiate-side polarization plates 444 disposed on thedownstream of the respective incident-side polarization plates 442, anda cross dichroic prism 445 as a color-combining optical device.

The liquid crystal panels 441R, 441G and 441B use, for instance, apolycrystalline silicon TFT as a switching element, which has a pair ofopposing transparent substrates with liquid crystal sealed therebetween.The liquid crystal panels 441R, 441G and 441B irradiate the light beamincident thereon through the incident-side polarization plates 442 aftermodulating in accordance with image information.

The incident-side polarization plate 442 only transmits a polarizedlight in a predetermined direction out of the respective color lightsseparated by the color-separating optical system 42 and absorbs theother light beam, which has a substrate made of sapphire glass or thelike with a polarization film attached thereon.

The irradiation-side polarization plate 444 is also arrangedsubstantially in the same manner as the incident-side polarization plate442, which only transmits the polarized light in a predetermineddirection out of the light beam irradiated by the liquid crystal panels441R, 441G and 441B, where the polarization axis of the transmittedpolarized light is set orthogonal to the polarization axis of thepolarized light transmitted through the incident-side polarization plate442.

The cross dichroic prism 445 combines the optical image irradiated bythe irradiation-side polarization plate 444 and modulated for each colorlight to form a color image. In the cross dichroic prism 445, adielectric multi-layer film for reflecting the red light and adielectric multi-layer film for reflecting the blue light are formedalong the boundaries of four right-angle prisms approximately in anX-shape, the dielectric multi-layer films combining the three colorlights.

The above-described liquid crystal panels 441R, 441G and 441B, theirradiation-side polarization plates 444 and the cross dichroic prism445 are integrated as a unit.

FIG. 7 is an illustration showing the structure of the inner case 45.

The inner case 45 is a synthetic resin component formed by injectionmolding and the like, which includes a lower inner case 46 where theabove-described optical components 41, 42, 43 and 44 are housed, and alid-shaped upper inner case 47 for closing the upper opening of thelower inner case 46.

The lower inner case 46 has a light source housing 48 where the lightsource device 411 is housed, and a component housing 49 formed in acontainer where other optical components are housed except the lightsource device 411.

The light source housing 48 has an approximately box-shape, and openingsare respectively formed on a distal side near the component housing 49and on a side opposite thereto. The opening formed on the side near thecomponent housing 49 transmits a light beam irradiated by the lightsource device 411. The opening formed on the side opposite to the sidenear the component housing 49 serves as an opening through which thelight source device 411 is housed by inserting from the lateral side ofthe light source housing 48.

The component housing 49 is an approximately rectangular parallelepipedwith an upper side thereof being opened, an end thereof being connectedto the light source housing 48. A head 50 on which the projection lens 3is fixed by screws is attached to the other end of the component housing49. The head 50 places the projection lens 3 at a predetermined positionon the illumination optical axis set inside the inner case 45.

Though not specifically shown here, a plurality of grooves for slidablyfitting the optical components 412 to 415, 419, 421 to 423 and 431 to435 are formed at the component housing 49. The optical device 44 isplaced at a part of the component housing 49 adjacent to the head 50.

The upper inner case 47 closes an upper opening of the component housing49 of the lower inner case 46, but does not close above the opticaldevice 44. A plurality of openings 47A are formed at the upper innercase 47 by penetrating through it, so that the air having cooled theinside of the inner case 45 is discharged from the openings 47A.

(2-2) Structure of Control Board 5

As shown in FIG. 5, the control board 5 is disposed above the upperinner case 47 of the inner case 45. The control board 5 is a circuitboard having a processor such as a CPU (Central Processing Unit)installed thereon, which controls the operation of the entire projector1. The control board 5 controllably drives the liquid crystal panels441R, 441G and 441B based on the signal outputted by the above-describedinterface board. The liquid crystal panels 441R, 441G and 441B modulatethe light beam to form an optical image. Further, an operation signaloutputted by the circuit board of the above-described operation panel 26and the non-illustrated remote controller module is inputted to thecontrol board 5 and the control board 5 outputs a control command to thecomponents of the projector 1 based on the operation signal.

(2-3) Structure of Power Supply Unit 6

The power supply unit 6 for supplying the electric power to the lightsource device 411 and the control board 5 etc., is disposed along thelongitudinal direction of the front case 23 of the exterior case 2. Thepower source unit 6 has a power source block 61 containing a powersource circuit, a lamp drive block (not shown) disposed below the powersource block 61.

The power source block 61 supplies the electric power supplied from theoutside through the power cable connected to the inlet connector 22D3 tothe lamp drive block and the control board 5 etc. The power source block61 has a circuit board having a transformer for converting the inputtedalternate-current into a low-voltage direct-current and a converter forconverting the output of the transformer into a predetermined voltage onone side thereof, and a tube component 611 (shield component) coveringthe circuit board. The tube component 611 is made of aluminum and isformed in an approximately box-shape with both ends being opened.

The lamp drive block is a converter for supplying the electric power tothe above-described light source device 411 at a constant voltage. Thealternate-current electricity input from the power source block 61 iscommutated and converted into the direct-current electricity or thealternate-current electricity in rectangular wave by the lamp driveblock to be supplied to the light source device 411.

An exhaust fan 72 is provided at the lateral side of the power sourceunit 6 to discharge the air having cooled the power source unit 6through the opening where the louver 71 is attached. Further, a duct 73is provided between the power source unit 6 and the light source housing48 of the inner case 45, so that the air having cooled the light sourcedevice 411 inside the light source housing 48 is attracted by theexhaust fan 72 to be discharged from the opening through the duct 73.

(3) Projection Lens Position Adjuster 30

FIG. 8 shows the projection lens position adjuster 30. The projectionlens position adjuster 30 moves the projection lens 3 vertically (in theY3 and Y4 directions) and horizontally (in the X3 and X4 directions) toadjust the position of the projection area.

For adjusting the position of the projection lens 3, assume that an axisassociating the Y3 and Y4 directions represents a Y-axis, and an axisassociating the X3 and X4 directions represents an X-axis.

As shown in FIG. 9, according to the projection lens position adjuster30, when the projection lens 3 is moved to the uppermost position (inthe Y4 direction), the projection area can shift one screen higher(screen S2) than a screen S1 projected in a case that the projectionlens 3 is located on the reference position (approximately the center ofthe range where the projection lens 3 can move along the Y-axis).

When the projection lens 3 is moved to the lowermost position (in the Y3direction), the projection area can shift a half screen lower (screenS3) than the screen S1 projected in a case that the projection lens 3 islocated on the reference position (approximately the center of the rangewhere the projection lens 3 can move along the Y-axis).

When the projection lens 3 is moved to the rightmost position (in the X3direction) or the leftmost position (in the X4 direction), theprojection area can shift a half screen rightward (screen S4) orleftward (screen S5) as compared to the screen S1 projected in a casethat the projection lens 3 is located on the reference position(approximately the center of the range where the projection lens 3 canmove along the X-axis).

As shown in FIGS. 8 and 10, the projection lens position adjuster 30,which is fixed to the exterior case 2, includes a base 33 disposed byabutting on the rib 22A6 (FIG. 4), a mount 39 having a Y-table 34 and anX-table 35 both sliding on the base 33, a Y-table driver 31 causing theY-table 34 of the mount 39 to slide on the base 33, and an X-tabledriver 32 causing the X-table 35 to slide on the base 33.

Also, as shown in FIGS. 10 and 11, the base 33 has a base body 331 of anapproximately planarly-viewed rectangular plate, and extended parts 332extending from both ends of the base body 331 toward the Y-table 34 tobe approximately orthogonal to the base body 331.

An approximately square hole 331A is formed approximately at the centerof the base body 331 so that the projection lens 3 is inserted to thehole 331A and also moves inside the hole 331A. The hole 331A determinesthe range where the projection lens 3 can move.

Each distal end 333 in an extending direction of the extended part 332is arranged approximately in parallel to the base body 331. Edge of theY-table 34 in the X-axis direction are inserted to each part between thedistal ends 333 and the base body 331.

An extended part 332A out of the extended parts 332 has a T-shapedcross-section. A pair of bosses 333A1 are formed at a distal end 333A ofthe extended part 332A. The boss 333A1 is inserted to an elongated hole314B provided on a Y-slider 314 of the below-described Y-table driver31. An elongated hole 333A2 extending in the Y-axis direction is formedat the distal end 333A.

An attachment piece 333A3 approximately orthogonal to the distal end333A is formed at an upper part of the distal end 333A. Holes 333A4 and333A5 are formed at the attachment piece 333A3 to fix a dial 311 and agear 313 (described below) of the Y-table driver 31.

Another extended part 332B of the extended parts 332 has anapproximately L-shaped cross-section, with holes 333B1 for fixing abelow-described attachment 38 formed.

The mount 39 for attaching the projection lens 3 and for sliding on thebase 33 includes the Y-table 34 that slides on the base 33 in the Y-axisdirection and the X-table 35 that slides in the direction orthogonal tothe sliding direction of the Y-table 34 (in the X-direction).

As shown in FIGS. 11 and 12, the Y-table 34 is an approximatelyplanarly-viewed rectangular plate with dimensions of edges in the Y-axisand X-axis directions being shorter than those of the base 33. Both endsof the Y-table 34 in the X-axis direction are inserted to each partbetween the distal ends 333 and the base body 331 of the base 33, sothat the Y-table 34 slides on the base 33 in the Y-axis direction. Anapproximately ellipsoidal hole 341 extending in the X-axis direction isformed approximately at the center of the Y-table 34. The smallerdiameter (diameter in the Y-axis direction) of the hole 341 isapproximately the same as the diameter of the projection lens 3 whilethe larger diameter thereof (diameter in the X-axis direction) isapproximately the same as the length of the hole 331A of the base 33 inthe X-axis direction. The projection lens 3 is inserted to the hole 341.

An approximately rectangular hole 342 is formed at the Y-table 34adjacent to the hole 341. The hole 342 is used for fixing the Y-slider314 to the Y-table 34.

Attached to the Y-table 34 are a pair of pieces 343 vertically (in theY-axis direction) and oppositely disposed sandwiching the hole 341. Eachpiece 343 having an approximately L-shaped cross-section includes aperpendicular part 343A disposed orthogonal to the Y-table 34 and aparallel part 343B provided at the perpendicular part 343A extendingapproximately parallel to the Y-table 34. Ends of the X-table 35 areinserted to each part between the parallel part 343B and the Y-table 34.

As shown in FIG. 12, the X-table 35 is a planarly-viewed rectangularplate with the external dimension thereof being smaller than that of theY-table 34.

An approximately circular hole 351 where the projection lens 3 isinserted thereto to be held thereby is formed approximately at thecenter of the X-table 35. Namely, the projection lens 3 is attached tothe X-table 35. A pair of projections 352 are formed above the hole 351of the X-table 35. Both ends 353 of the X-table 35 in the Y-axisdirection are cut out, so that the thickness of the both ends 353 aresmaller than other parts. The ends 353 are respectively inserted to thepieces 343 of the Y-table 34 in order that the ends 353 of the X-table35 slide inside the pieces 343. In other words, the X-table 35 slides onthe base 33 via the Y-table 34.

As shown in FIG. 11, the Y-table driver 31 for linearly driving theY-table 34 on the base 33 includes the dial 311 and a transmitter 312(first transmitter) to transmit the rotation of the dial 311 to theY-table 34.

The dial 311 has an approximately colunmar dial body 31lA exposedthrough a hole for the dial provided at the upper side 21A of the uppercase 21 of the exterior case 2 (FIG. 1), a gear section 311B attached toa circular face of the dial body 311A, and a shaft 311C attached to thegear section 311B.

The shaft 311C is inserted to the hole 333A4 of the attachment piece333A3 of the base 33, and fixed by a fixing ring 315.

The transmitter 312 includes a gear 313 that meshes with the gearsection 311B of the dial 311 and the Y-slider 314 that meshes with thegear 313 to slide as the gear 313 rotates.

A shaft of the gear 313 is inserted to the hole 333A5 of the attachmentpiece 333A3 of the base 33, and fixed by the fixing ring 315.

The Y-slider 314 is an elongated component extending in the Y-axisdirection, with a part of an end in the shorter-side direction is bentopposite to the base 33. The bent part is cut like sawtooth to serve asa meshing section 314A for meshing with the gear 313.

A pair of elongated holes 314B extending along the longitudinaldirection of the Y-slider 314 and a recess 314C are formed on theY-slider 314.

The bosses 333A1 of the base 33 are inserted to the elongated holes314B.

The recess 314C is formed between the pair of elongated holes 314B withits cross-section being V-shaped. A projection 314D is formed at theapproximately center of the other end of the Y-slider 314 in theshorter-side direction. The projection 314D extends toward the base 33to be fitted to the hole 342 of the Y-table 34 and also inserted to theelongated hole 333A2 of the base 33.

An elongated spring piece (biasing member) 36 extending in the Y-axisdirection is attached on the Y-slider 314. Both ends 362 of the springpiece 36 in the longitudinal direction are bent to be approximatelyL-shaped. Holes 362A where screws B1 are inserted are formed at the bothends 362, so that the screws B1 are inserted to the bosses 333A1 throughthem and the elongated holes 314B. Accordingly, the spring piece 36 isfixed to the bosses 333A1 of the base 33. Thus, the spring piece 36would not move as the Y-slider 314 slides.

Approximately the center part of the spring piece 36 in the longitudinaldirection is dented in a V-shape to serve as a protrusion 361 projectedtoward the Y-slider 314. The protrusion 361 is biased toward theY-slider 314 to abut on the Y-slider 314, so that the protrusion 361engages with the recess 314C of the Y-slider 314 when the Y-slider 314slides to move the projection lens 3 to a reference position, forinstance, approximately to the center in the Y-axis direction.

Specifically, according to the present exemplary embodiment, the springpiece 36 with the protrusion 361 formed and the Y-slider 314 with therecess 314C formed serve as a recognizer for recognizing the referenceposition in the Y-axis direction (approximately the center in the Y-axisdirection).

As shown in FIG. 12, the X-table driver 32 for linearly driving theX-table 35 on the base 33 includes a dial 321 and a transmitter 322(second transmitter) to transmit the rotation of the dial 321 to theX-table 35.

The dial 321, which has a configuration approximately the same as thedial 311, includes an approximately columnar dial body 321A exposedthrough a hole for the dial provided at the upper side 21A of the uppercase 21 (FIG. 1), a gear section 321B attached to a circular face of thedial body 321A, and a shaft 321C attached to the gear section 321B.

The dial 321 is fixed on the base 33 through a platy attachment 38.Specifically, the dial 321 is fixed-by inserting a shaft 321C of thedial 321 to a hole 381 and attaching a fixing ring 315. It is to benoted that a hole 382 is also provided adjacent to the hole 381, so thata shaft of the gear 323 is inserted thereto.

The transmitter 322 includes a gear 323 that meshes with the gearsection 321B of the dial 321 and the X-slider 324 that meshes with thegear 323 to slide as the gear 323 rotates.

The X-slider 324 is an elongated component extending in the X-axisdirection, with a part of an elongated edge thereof being cut likesawtooth. The sawtooth part serves as a meshing section 324A whichmeshes with the gear 323.

A pair of elongated holes 324B extending along the longitudinaldirection of the X-slider 324 and a recess 324C are formed on theX-slider 324.

A pair of bosses 383 formed on the attachment 38 are inserted to theelongated holes 324B.

The recess 324C is formed between the pair of elongated holes 324B withits cross-section being V-shaped.

An extended part 324D extending downward in FIG. 12 is formedapproximately at the center of the other longitudinal edge of theX-slider 324. The elongated part 324D is fitted to a part between theprojections 352 of the X-table 35.

Since the X-table 35 is disposed on the Y-table 34, the X-table 35 movesdownward when the Y-table 34 moves downward. At this time, the extendedpart 324D of the X-slider 324 slides between the projections 352,however, the extended part 324D still has a length not to be releasedfrom the projections 352 even when the X-table 35 moves to the lowermostposition. Namely, the length of the extended part 324D in the extendingdirection is longer than a distance where the X-table 35 can verticallymove.

An elongated spring piece (biasing member) 37 extending in the X-axisdirection is attached on the X-slider 324. The spring piece 37 is formedapproximately the same as the spring piece 36, with both ends 372 of thespring piece 37 in the longitudinal direction are bent to beapproximately L-shaped. Holes 372A where screws B1 are inserted areformed on each end 372, so that the screws B1 are inserted to the pairof bosses 383 formed on the attachment 38 through the elongated holes324B. Thus, the spring piece 37 is fixed to the attachment 38 fixed onthe base 33.

Approximately the center part of the spring piece 37 in the longitudinaldirection is dented in a V-shape to serve as a protrusion 371 projectedtoward the X-slider 324. The protrusion 371 is biased toward theX-slider 324 to abut on the X-slider 324, so that the protrusion 371engages with the recess 324C of the X-slider 324 when the X-slider 324slides to move the projection lens 3 to a reference position, forinstance, to approximately the center in the X-axis direction.

Specifically, according to the present exemplary embodiment, the springpiece 37 with the protrusion 371 formed and the X-slider 324 with therecess 324C formed serve as a recognizer for recognizing the referenceposition in the X-axis direction (approximately the center in the X-axisdirection).

The position adjustment of the projection lens 3 by the projection lensposition adjuster 30 will be described below with reference to FIGS. 8,11 and 12 mainly.

Firstly, the movement of the projection lens 3 in the Y-axis directionwill be described.

It is assumed that the projection lens 3 is positioned at the uppermostposition in the Y-axis direction.

A part of the dial 311 exposed from the exterior case 2 is rotateddownward (in the Y1 direction in FIG. 1), i.e., the dial 311 is rotatedin a direction shown by an arrow R1 in FIG. 8. With the rotation, thegear 313 is rotated in an R2 direction. The rotation of the gear 313causes the Y-slider 314 sliding downward (in the Y3 direction). Thebosses 333A1 then slide inside the elongated holes 314B of the Y-slider314. The projection 314D of the Y-slider 314 slides inside the elongatedhole 333A2 of the base 33.

Since the projection 314D is fitted to the hole 342 of the Y-table 34,the Y-table 34 also moves downward (in the Y3 direction) as the Y-slider314 moves. Since the ends of the X-table 35 are inserted to the pieces343 of the Y-table 34, the X-table 35 moves downward as the Y-table 34moves. Also, since the projection lens 3 is fixed on the X-table 35, theprojection lens 3 moves downward (in the Y3 direction) concurrently.

Note that, the spring piece 36 is fixed on the base 33, so that thespring piece 36 would not be moved even when the Y-slider 314 is moved.The protrusion 361 of the spring piece 36 abuts on the Y-slider 314, andconsequently, friction may be created between the protrusion 361 and theY-slider 314.

Further, when the dial 311 is rotated so that the projection lens 3 ismoved approximately to the center in the Y-axis direction of the hole331A formed on the base 33, the protrusion 361 of the spring piece 36engages with the recess 314C of the Y-slider 314. Accordingly, thefriction created between the protrusion 361 of the spring piece 36 andthe Y-slider 314 is reduced, thus reducing a rotation torque of the dial311.

When the dial 311 is further rotated, the engagement between theprotrusion 361 of the spring piece 36 and the recess 314C of theY-slider 314 is released, thus causing large friction again between theprotrusion 361 and the Y-slider 314.

Next, the movement of the projection lens 3 in the X-axis direction willbe described.

It is assumed that the projection lens 3 is positioned at the rightmostposition when the projector 1 as seen from the rear side.

A part of the dial 321 exposed from the exterior case 2 is rotatedleftward as seen from the rear side of the projector 1 (in the X2direction in FIG. 1), i.e., the dial 321 is rotated in a direction shownby an arrow R3 in FIG. 8. With the rotation of the dial 321, the gear323 is rotated in an R4 direction. As the gear 323 is rotated, theX-slider 324 moves leftward (in the X4 direction) as seen from the rearside of the projector 1. The bosses 383 of the attachment 38 slideinside the elongated holes 324B of the X-slider 324.

Since the extended part 324D of the X-slider 324 is fitted to the partbetween the projections 352 of the X-table 35, the X-table 35 slides onthe Y-table 34 as the X-slider 324 moves. The projection lens 3concurrently moves leftward (in the X4 direction).

Note that the spring piece 37 is fixed to the bosses 383 of theattachment 38 not to move along with the movement of the X-slider 324.The protrusion 371 of the spring piece 37 abuts on the X-slider 324, andconsequently, friction may be created between the protrusion 371 and theX-slider 324.

Further, when the dial 321 is rotated so that the projection lens 3 ismoved approximately to the center in the X-axis direction of the hole331A formed on the base 33, the protrusion 371 of the spring piece 37engages with the recess 324C of the X-slider 324. Accordingly, thefriction created between the protrusion 371 of the spring piece 37 andthe X-slider 324 is reduced, thus reducing a rotation torque of the dial321.

When the dial 321 is further rotated, the engagement between theprotrusion 371 of the spring piece 37 and the recess 324C of theX-slider 324 is released, thus causing large friction again between theprotrusion 371 and the X-slider 324.

While it is described in this exemplary embodiment the case that theprojection lens 3 moves from the uppermost position to the lowermostposition, and that the projection lens 3 moves from the right side tothe left side as seen from the rear side of the projector 1,alternatively, the same description can be applied when the projectionlens 3 moves from the lowermost position to the uppermost position, andwhen the projection lens 3 moves from the left side to the right side.

(4) Light Shielding Mechanism

Now, the light shielding structure of the projection lens 3 will bedescribed below with reference to FIGS. 13 to 16.

What provided around the projection lens 3 are the first light shield 11for closing the gap between the opening 231 of the front case 23 and theperiphery of the projection lens 3, and the second light shield 12 forclosing the gap between the projection lens 3 and the hole 331A of thebase 33 of the projection lens position adjuster 30.

As shown in FIGS. 14 and 15, the first light shield 11 has a ring 111, ashield body 112 and a fixing plate 113.

The ring 111 is held at a groove 3A1 circularly formed on the peripheryof a lens-holding barrel 3A of the projection lens 3 in a loosely fittedmanner. Thus, even if the lens-holding barrel 3A of the projection lens3 is rotated at the focus adjustment etc., the ring 111 would not berotated. A groove 111A having an approximately angular C-shapedcross-section is formed at the periphery of the ring 111.

The shield body 112, which is attached on the periphery of the ring 111,includes a ring-shaped elastic member 112A and a pair of attachmentpieces 112B extending outward from the elastic member 112A.

The elastic member 112A is disposed to extend between the ring 111 and aperipheral edge of the opening 231 of the front case 23. The elasticmember 112A is made of a thin platy rubber dented opposite to the frontcase 23, the elastic member 112A equipped with a deformable part 112A1having an approximately U-shaped cross-section orthogonal to a radialdirection of the projection lens 3, and attachments 112A2 and 112A3respectively disposed on the internal peripheral edge and the externalperipheral edge of the deformable part 112A1.

The deformable part 112A1 deformable along with the position adjustmentof the projection lens 3 is formed thinner than the attachments 112A2and 112A3.

The attachment 112A2 disposed on the internal peripheral edge of thedeformable part 112A1 is inserted to the groove 111A of the ring 111 tobe fixed thereon.

The attachment 112A3 disposed on the external peripheral edge of thedeformable part 112A1 is bent opposite to the front case 23 to beinserted to a dented part of the fixing plate 113 (described below). Thefixing plate 133 is fixed on the peripheral edge of the front case 23,so that the deformable part 112A1 of the shield body 112 closes the gapbetween the ring 111 attached no the projection lens 3 and the opening231 of the front case 23.

The attachment piece 112Bis fixed on the external peripheral edge of thedeformable part 112A1, and disposed along the peripheral edge of thedeformable part 112A1. The attachment piece 112B is used for attachingthe shield body 112 to the front case 23.

The fixing plate 113 used for fixing the shield body 112 to the frontcase 23, is disposed on the shield body 112 opposite to the front case23. The fixing plate 113 includes a ring 113A to which the projectionlens 3 is inserted, and a fixing piece 1131B extending outward from thering 113A. The ring 113A is dented opposite to the shield body 112, sothat the attachment 112A3 disposed on the external peripheral edge ofthe deformable part 112A1 of the shield body 112 is inserted to thedented part.

The fixing piece 1133B is fixed to the front case 23, with holes 113B1for inserting screws B2 being formed. When the fixing piece 113B isfixed to the front case 23, the attachments 112B and 112A3 of the shieldbody 112 are sandwiched to be fixed between the fixing piece 113B and arib 235 which is formed on the peripheral edge of the opening 231 of thefront case 23.

With the configuration of the above-described first light shield 11,when the projection lens 3 is moved, the deformable part 112A1 of theshield body 112 is deformed. For example, when the projection lens 3 ismoved upward (in the Y4 direction in FIG. 13), an upper part of thedeformable part 112A1 is compressed whereas a lower part thereof isstretched.

Next, the second light shield 12 will be described with reference toFIGS. 15 and 16.

In the above-described projection lens position adjuster 30, when theX-table 35 holding the projection lens 3 is moved leftward (in the X4direction in FIG. 8) or is moved rightward (in the X3 direction in FIG.8) as seen from the rear side of the projector 1, a gap may be generatedbetween the X-table 35 and the hole 341 of the Y-table 34, or betweenthe X-table 35 and the hole 331A of the base 33. Accordingly, the lightmay leak from the gap. The second light shield 12 is provided in orderto close the gap. The second light shield 12 attached to the inside ofthe base 33 of the projection lens position adjuster 30, includes ashield body 122 and a fixing plate 123.

The shield body 122, which is attached on the periphery of thelens-holding barrel 3A of the projection lens 3, includes a ring-shapedelastic member 122A and a attachment piece 122B extending outward fromthe elastic member 122A.

The elastic member 122A is made of a thin platy rubber dented oppositeto the front case 23, the elastic member 122A equipped with a deformablepart 122A1 having an approximately U-shaped cross-section orthogonal tothe radial direction of the projection lens 3, and attachments 122A2 and122A3 respectively disposed on the internal peripheral edge and theexternal peripheral edge of the deformable part 122A1.

The deformable part 122A1 deformable along with the position adjustmentof the projection lens 3 is formed thinner than the attachments 122A2and 122A3.

The attachment 122A2 disposed on the internal peripheral edge of thedeformable part 122A1 is fixed to the periphery of the lens-holdingbarrel 3A of the projection lens 3.

The attachment 122A3 disposed on the external peripheral edge of thedeformable part 122A1 is fixed to the peripheral edge of the hole 331Aof the base 33 of the projection lens position adjuster 30. Accordingly,the deformable part 122A1 closes the gap between the periphery of theprojection lens 3 and the hole 331A of the base 33.

The attachment 122B is a rectangular plate, where holes 122B1 to beinserted to the bosses 334 formed on the base 33 are formed.

The fixing plate 123 used for fixing the shield body 122 to the base 33,is disposed on the shield body 122 opposite to the base 33.

The fixing plate 123 is an approximately planarly-viewed rectangularsheet-metal, with a circular opening 123A for inserting the projectionlens 3 being formed at the center thereof. A pair of spring pieces 123Care provided on the fixing plate 123 approximately at the center of theend along the Y-axis direction.

Holes 123B for inserting screws B3 are formed on four corners of thefixing plate 123. When the screws B3 are inserted to the holes 123B tofix the fixing plate 123 to the base 33, the attachment 122A3 and theattachment piece 122B of the shield body 122 are sandwiched between theperipheral edge of the opening of the fixing plate 123 and the base 33.

With the configuration of the above-described second light shield 12,when the projection lens 3 is moved, the deformable part 122A1 of theshield body 122 is deformed. For example, when the projection lens 3 ismoved upward (in the Y4 direction in FIG. 13), an upper part of thedeformable part 122A1 is compressed whereas a lower part thereof isstretched.

(5) Advantages of the Exemplary Embodiment

According to the present exemplary embodiment, following advantages canbe obtained.

(5-1) When the part of the dial 311 of the projection lens positionadjuster 30 exposed form the exterior case 2 is moved downward (in theY1 direction), the projection lens 3 is moved downward (in the Y3direction). When the part of the dial 311 exposed from the exterior case2 is moved upward (in the Y2 direction), the projection lens 3 is movedupward (in the Y4 direction). Further, when the part of the dial 321exposed from the exterior case 2 is moved rightward (in the X1direction) as seen from the rear side of the projector 1, the projectionlens 3 is moved rightward (in the X3 direction) as seen from the rearside of the projector 1. When the part of the dial 321 exposed from theexterior case 2 is moved leftward (in the X2 direction) as seen from therear side of the projector 1, the projection lens 3 is moved leftward(in the X4 direction) as seen from the rear side of the projector 1.

As described above, as seen from the projector 1, since the directionwhere the projection lens 3 is moved and the direction where the dials311 and 321 are rotated are correspondent, the moving direction of theprojection lens 3 can easily be recognized. Accordingly, a user maysmoothly adjust the position of the projection lens 3.

Especially, when the projection lens 3 is moved in two directionsorthogonal to each other, the user is difficult to recognize the movingdirection of the projection lens 3 in a case that the rotary directionof the dial and the moving direction of the projection lens 3 are notcorrespondent, thus confusing the user. However, in the presentexemplary embodiment, since the rotary direction of the dials 311 and321 and the moving direction of the projection lens 3 are approximatelycorrespondent, the user can easily recognize the moving direction of theprojection lens 3, thus enhancing or improving usability.

(5-2) In the present exemplary embodiment, the rotation of the dials 311and 321 can be converted into the linear driving only by providing thegears 313 and 323 respectively between the dials 311, 321 and thesliders 314, 324, so that the moving direction of the projection lens 3and the rotary direction of the dials 311 and 321 can be correspond asseen from the rear side of the projector 1, thus simplifying thestructure of the projection lens position adjuster 30.

(5-3) Since the recognizer for recognizing the reference position of theprojection lens 3 is provided at the projection lens position adjuster30, the recognizer changing the rotation torque of the dials 311 and321, i.e., the recognizer changing the force necessary for rotating thedials 311 and 321, the position of the projection lens 3 can easily berecognized while rotating the dials 311 and 321. Specifically, theprotrusions 361 and 371 of the spring pieces 36 and 37 are biased towardand abutted on the Y-slider 314 and the X-slider 324 until theprojection lens 3 reaches the reference position, friction is createdbetween the protrusions 361, 371 and the Y-slider 314, X-slider 324. Thefriction is the rotation torque of the dials 311 and 321. When theprojection lens 3 reaches the reference position, the recesses 314C,324C and the protrusions 361, 371 are respectively engaged, so that therotation torque of the dials 311 and 321 are reduced. Thus, thereference position of the projection lens 3 can easily be recognized.

The easy recognition enhances or improves the usability for the user.

(5-4) Further, since the reference position the projection lens 3 can berecognized only by engaging the recesses 314C, 324C with the protrusions361, 371, the structure of the projection lens position adjuster 30would not be complicated even if the recognizer is provided forrecognizing the reference position.

(5-5) Since the recesses 314C and 324C are respectively formed on theX-slider 324 of the transmitter 322 and the Y-slider 314 of thetransmitter 312 directly connected to the dials 311 and 321, the changeof the friction when the recesses 314C, 324C and the protrusions 361,371 are engaged can directly be transmitted to the dials 311 and 321.Accordingly, the change of the rotation torque of the dials 311 and 321can securely be recognized by the user, thus further enhancing orimproving the usability.

(5-6) Since the reference position where the recesses 314C, 324C engagewith the protrusions 361, 371 is approximately the mid position in themoving direction of the projection lens 3, the user can easily recognizethe center. Accordingly, easy recognition of the center can be effectiveespecially when the user uses the projector 1 with an optical axis ofthe projection lens 3 thereof corresponding to the center of theprojected image on the screen.

(5-7) Since the protrusions 361, 371 and the recesses 314C, 324C haveapproximately V-shaped cross sections, when the engagement between therecesses 314C, 324C and the protrusions 361, 371 are released, it can beconducted only by moving the recesses 314C, 324C from the engagementstate.

(5-8) When the projection lens 3 is moved to the uppermost position bythe projection lens position adjuster 30, the projection area can shiftone screen higher than a screen projected in a case that the projectionlens 3 is located on the reference position. Since the projection areacan shift one screen higher, it is possible to project the image withthe projector 1 placing at a level lower than usual, for example on thefloor. If there is a vaulted ceiling, the projector 1 can be placed onthe ceiling upside down to project downward.

When the projection lens 3 is moved to the lowermost position, theprojection area can shift a half screen lower than the screen projectedin the case that the projection lens 3 is located on the referenceposition. Accordingly, it is possible to use the projector 1 placing ata level relatively higher than usual, for example on a shelf.

As described above, the projector 1 of the present exemplary embodimentcan project the image from the higher level toward the lower level, orfrom the lower level toward the higher level, so that the level wherethe projector 1 is placed would not be restricted, thus enhancing orimproving the usability of the projector 1.

(5-9) When the projection lens 3 is moved to the rightmost position orthe leftmost position by the projection lens position adjuster 30, theprojection area can shift a half screen rightward or leftward ascompared to the screen projected in the case that the projection lens 3is located on the reference position. Accordingly, even when the opticalaxis of the projection lens 3 is deviated rightward or leftward from thecenter position of the screen, the projector 1 can project the image atthe center of the screen pretty securely. With this configuration, theprojector 1 can be used in the space where the projector 1 is limited tobe placed, such as a small room.

(5-10) Since the first light shield 11 has the elastic member 112Adisposed to extend between the ring 111 attached to the projection lens3 and the peripheral edge of the opening 231 of the front case 23, thegap between the projection lens 3 and the opening 231 can be closed bythe elastic member 112A. Accordingly, the light leakage from the gap canbe reduced or prevented.

(5-11) Since the elastic member 112A of the first light shield 11 isattached to the ring 111 provided on the projection lens 3, the elasticmember 112A is compressed or stretched along with the movement of theprojection lens 3. Accordingly, even when the projection lens 3 is movedto adjust the position thereof, the gap between the projection lens 3and the opening 231 can securely be closed, thus reducing or preventingthe light leakage.

Further, since the gap between the projection lens 3 and the opening 231can securely be closed, the invasion of the dusts from the gap can alsobe reduced or prevented.

(5-12) Since the first light shield 11 can follow the movement of theprojection lens 3 with the elastic member 112A compressed and stretched,a shield plate itself would not follow unlike the related art.Therefore, since the dimension of the exterior case along the movingdirection of the projection lens is not required to be longer in orderto secure the range where the light shield moves inside the exteriorcase.

(5-13) Since the ring 111 is held on the outer periphery of thelens-holding barrel 3A of the projection lens 3 in a loosely fittedmanner, even if the lens-holding barrel 3A is rotated at the focusadjustment etc., the ring 111 would not be rotated. Since the elasticmember 112A is fixed on the ring 111, it can be prevented that theelastic member 112A is twisted along with the rotation of thelens-holding barrel 3A of the projection lens 3.

(5-14) Since the second light shield 12 having the elastic member 122Adisposed to extend between the periphery of the projection lens 3 andthe peripheral edge of the hole 331A of the base 33 of the projectionlens position adjuster 30 is provided, the light leakage from the gapbetween the projection lens position adjuster 30 and the projection lens3 can be reduced or prevented.

Since the second light shield 12 has the elastic member 122A fixed tothe projection lens 3 in the same manner as the first light shield 11,the elastic member 122A is compressed or stretched to follow themovement of the projection lens 3. Accordingly, even when the projectionlens 3 is moved, the gap between the projection lens position adjuster30 and the projection lens 3 can securely be closed, thus reducing orpreventing the light leakage.

(5-15) Since the second light shield 12 can securely close the gapbetween the projection lens 3 and the projection lens position adjuster30, the invasion of the dusts from the gap can also be reduced orprevented.

(5-16) Since there are provided two light shields of the first lightshield 11 and the second light shield 12, the light leakage and theinvasion of the dusts can securely be reduced or prevented.

(5-17) There are provided the rib 234 at the front case 23, the rib 22A6at the bottom side 22A of the lower case 22 and the rib at the upperside 21A of the upper case 21 of the exterior case 2, to form the lenshouse with these ribs surrounding around the periphery of the projectionlens 3. The ribs 22A6 and the rib of the upper side 21A of the uppercase 21 abut on the base 33. Since the second light shield 12 isprovided for closing the gap between the projection lens 3 and the hole331A of the base 33, the lens house is sealed by the second light shield12. Even when the dusts invade the exterior case 2 through the holeswith the dials 311 and 321 being exposed through, the dusts would notinvade the optical unit 4 etc. since the lens house is sealed.Accordingly, the adhesion of the dusts to the liquid crystal panel 441etc. can be reduced or prevented, thus enhancing the reliability of theprojector 1.

(5-18) Since the deformable part 112A1 of the first light shield 11 andthe deformable part 122A1 of the second light shield 12 are thinned, theform of which can be deformed along with the position adjustment of theprojection lens 3. Therefore, providing the light shields 11 and 12 donot make the position adjustment of the projection lens 3 difficult, butthe position of the projection lens 3 can smoothly be adjusted with thelight shields 11 and 12 provided.

(5-19) If the deformable part is flat instead of the sag structure, theelastic force is largely generated on the deformable part when thedeformable part is pulled with large force along with the positionadjustment of the projection lens 3, thus the deformable part unlikelyfollowing the movement of the projection lens 3.

On the other hand, in the present exemplary embodiment, since thedeformable parts 112A1 and 122A1 have approximately U-shaped crosssection, and the platy elastic members are sagged. Even when thedeformable parts 112A1 and 122A1 are pulled with large force along withthe position adjustment of the projection lens 3, the sag of thedeformable parts 112A1 and 122A1 is only required to be stretched, andthe elastic force is unlikely generated, thus the deformable parts 112A1and 122A1 easily following the movement of the projection lens 3.

Since the deformable parts 112A1 and 122A1 easily follow the movement ofthe projection lens 3, the position adjustment of the projection lens 3is unlikely to be difficult.

(5-20) Since the attachment 112A3 of the elastic member 112A of thefirst light shield 11 is sandwiched between the fixing plate 113 and thefront case 23, the elastic member 112A can securely be fixed. Similarly,since the attachment 122A3 of the elastic member 122A of the secondlight shield 12 is sandwiched between the fixing plate 123 and the base33, the elastic member 122A can securely be fixed.

(5-21) Since the attachment 112A2 is formed to be thick, the attachment112A2 can be fitted to the groove 111A of the ring 111 to be securelyfixed to the ring 111.

Since the attachment 112A3 is also formed to be thick, the attachment112A3 can securely be fitted to the dented part of the ring 113A of thefixing plate 113, thus securely fixing the attachment 112A3 between thefixing plate 113 and the front case 23. As described above, since theattachments 112A2 and 112A3 of the elastic member 112A of the shieldbody 112 can securely be fixed to the ring member 111 and the front case23, the attachments 112A2 and 112A3 would not be detached from the ring111 and the front case 23 along with the position adjustment of theprojection lens 3, and consequently, the gap between the projection lens3 and the opening 231 of the front case 23 can securely shield thelight.

Similarly, since the attachments 122A2 and 122A3 are also formed to bethick, the attachments 122A2 and 122A3 can tightly attached to theperiphery of the lens-holding barrel 3A of the projection lens 3 and tothe base 33, thus securely closing the gap between the projection lens 3and the projection lens position adjuster 30.

[Second Exemplary Embodiment]

Next, a second exemplary embodiment of the present invention will bedescribed below. Incidentally, in the following description, the samereference numeral will be attached to the same components as the aboveto omit the description thereof. Further, in this embodiment, componentswhich are not particularly described herein may be configured in thesame manner as the first exemplary embodiment.

In the above exemplary embodiment, the spring piece 37 abuts on theX-slider 324 while the protrusion 371 of the spring piece 37 engageswith the recess 324C formed on the X-slider 324. In contrast, in thepresent exemplary embodiment, as shown in FIG. 17, the protrusion 371engages with a recess 321F formed on a shaft 321C′ of a dial 321′. Thatis, in the present exemplary embodiment, the recognizer for recognizingthe reference position is constituted of the spring piece 37 and theshaft 321C′ of the dial 321′.

The shaft 231C′ has a large-diameter part 321D attached to the gearsection 321B and a small-diameter part 321E attached to thelarge-diameter part 321D. The recess 321F is formed by cutting a part ofthe large-diameter part 321D in a V-shape.

A notch 321G is formed along the periphery of the small-diameter part321E. The fixing ring 315 is attached to the notch 321G.

The dial 321′ is attached to an attachment 38′. The attachment 38′ hasapproximately the same structure as the attachment 38 of the aboveexemplary embodiment, except that a pair of projections 384 projectingtoward the dial body 321A are formed thereon.

Holes 384A extending in a direction (the Y-axis direction) orthogonal tothe projecting direction of the projection 384 are respectively formedat pair of projections 384. Ends 372 of the spring piece 37 are fixed tothe holes 384A by way of screws B1.

The protrusion 371 of the spring piece 37 fixed on the projections 384is biased toward the large-diameter part 321D of the dial 321′ to abuton the large-diameter part 321D.

In the present exemplary embodiment, the projection lens 3 is moved froman end in the movable range in the X-axis direction (e.g., the rightmostposition as seen from the rear side of the projector 1) to the other end(the leftmost position as seen from the rear side of the projector 1) bythe dial 321′ rotating for 2.2 rounds.

The movement of the projection lens 3 in the X-axis direction will bedescribed below with reference to FIG. 18.

It is assumed that the projection lens 3 is positioned at the rightmostposition when the projector 1 as seen from the rear side.

Firstly, the dial 321′ is rotated leftward as seen from the rear side ofthe projector 1 (in the X2 direction in FIG. 1). Since the protrusion371 of the spring piece 37 abuts on the large-diameter part 321D of thedial 321′, friction may be created between the protrusion 371 of thespring piece 37 and the large-diameter part 321D of the dial 321′. Whenthe dial 321′ is rotated and the rotation amount reaches 0.1 rounds, theprotrusion 371 of the spring piece 37 engages with the recess 321F ofthe dial 321′. Therefore, the friction between the protrusion 371 andthe dial 321′ is reduced, thus reducing the rotation torque of the dial321′.

When the dial 321′ is further rotated, the engagement between theprotrusion 371 and the recess 321F is released, so that the frictionbetween the protrusion 371 and the large-diameter part 321D increasesagain.

When the rotation amount of the dial 321′ reaches 1.1 rounds, theprojection lens 3 is positioned approximately at the center in theX-axis direction. At this time, the protrusion 371 again engages withthe recess 32 IF, accordingly the rotation torque of the dial 321′ isreduced.

When the dial 321′ is further rotated, the engagement between theprotrusion 371 and the recess 321F will be released again.

When the rotation amount of the dial 321′ reaches 2.1 rounds, theprotrusion 371 again engages with the recess 321F, the rotation torqueof the dial 321′ is reduced.

Then, when the dial 321′ is further rotated, the engagement between theprotrusion 371 and the recess 321F is released. Further, when therotation amount reaches 2.2 rounds, the projection lens 3 is positionedat the leftmost position in the movable range.

Incidentally, while the structure of the dial 321′ and the movement ofthe projection lens 3 only in the X-axis direction are disclosed in thepresent exemplary embodiment, the same structure is applied to the dialthat moves the projection lens 3 in the Y-axis direction, and theprojection lens 3 moves from the uppermost position (lowermost position)to the lowermost position (uppermost position) by the dial being rotatedfor 2.2 rounds in the same manner as the dial 321′.

(6) Advantages of the Exemplary Embodiment

According to the above present exemplary embodiment, followingadvantages can be obtained in addition to those approximately the sameas (5-1) to (5-4) and (5-6) to (5-21) in the first exemplary embodiment.

(6-1) Since the protrusion 371 of the spring piece 37 abuts on the shaft321C′ of the dial 321′, the change of the friction when the protrusion371 engages with the recess 321F is likely to transmitted to the dialbody 321A of the dial 321′. Therefore, the user can securely recognizethe change of the rotation torque.

(6-2) The change of the rotation torque is created not onlyapproximately at the center in the moving direction of the projectionlens 3, but also around the end in the moving direction, so that theuser can easily recognize the position of the projection lens 3.

Incidentally, the scope of the present invention is not restricted tothe above-described exemplary embodiments, but includes modificationsand improvements as long as an object of the present invention can beaddressed or achieved.

For example, while the change of the rotation torque of the dials 311and 321 are created when the projection lens 3 is positionedapproximately at the center in the moving direction of the projectionlens 3, it may be available that the rotation torque is created on thedial or a part around the end in the moving direction in the same manneras the second exemplary embodiment.

Or, in the respective exemplary embodiments, it is also available thatthe change of the rotation torque is created per predetermined distance.Accordingly, the position of the projection lens 3 can securely berecognized by the user.

In the respective exemplary embodiments, while the protrusions 361 and371 are formed at the spring pieces 36 and 37, and the protrusions 361and 371 are biased toward the Y-slider 314, a ball etc. can be appliedas the protrusion to be biased toward the Y-slider 314 instead.

In the respective exemplary embodiments, the protrusions 314C, 324C and321F are respectively formed at the sliders 314 and 324, and also at theshaft 321C′ of the dial 321′ while the protrusions 361 and 371 areformed at the spring pieces 36 and 37, it is not limited thereto. Theprotrusions can be formed at the slider and at the shaft of the dialwhile the recesses are formed at the spring pieces.

In the respective exemplary embodiments, the Y-table 34 is placed on thebase 33 while the X-table 35 is placed on the table 34, it is notlimited thereto. The X-table may be placed on the base 33 with theY-table arranged on the X-table.

In the respective exemplary embodiments, although the first light shield11 and the second light shield 12 have the fixing plates 113 and 123,the fixing plate may not be provided. Accordingly, the number of thecomponents can be reduced.

In the respective exemplary embodiments, while the deformable parts112A1 and 122A1 of the first light shield 11 and the second light shield12 are formed thinner than the attachments 112A3, 112A2, 122A3 and122A2, the deformable part can have approximately the same thickness asthe attachments 112A3, 112A2, 122A3 and 122A2.

In the respective exemplary embodiments, the second light shield 12 isattached on the periphery of the projection lens 3, however, the secondlight shield 12 may not be provided. For example, the projection lensposition adjuster may not have the second light shield 12 when the gapis not generated between itself and the projection lens, or when thefirst light shield 11 is enough to shield the light without the secondlight shield 12. Accordingly, the number of the components and the costof the projector 1 can be reduced.

In the respective exemplary embodiments, though a projector using threeoptical modulators are taken as an example in the above exemplaryembodiment, exemplary embodiments of the present invention may beapplied to a projector using a single optical modulator, two opticalmodulators or more than three optical modulators.

In the respective exemplary embodiments, though the example in which thepresent invention is applied to the transmission type projector isdescribed, the present invention may be applied to a reflection typeprojector. Note that, the “transmission type” indicates a type in whichan optical modulator such as a liquid crystal panel transmits a light,whereas the “reflection type” indicates a type in which an opticalmodulator reflects a light. Besides, such an optical modulator is notlimited to a liquid crystal panel, and may be the one using a micromirror. Incidentally, while the configuration of an optical systembetween a light source and a projection optical system may varyaccording to the kind of an optical modulator as well as a light source,the present invention can be applied to any type of projector equippedwith a projection optical system.

1. A projector that forms an optical image by modulating a light beamirradiated by a light source in accordance with image information andprojects the optical image by a projection optical system in an enlargedmanner, comprising: a projection optical system position adjuster thatmoves the projection optical system on a plane orthogonal to alight-projecting direction and adjusts a position of a projection areaof the projection optical system; and a casing in which the projectionoptical system position adjuster and the projection optical system arehoused; the projection optical system position adjuster having a firstdial and a second dial exposed from the casing when the first dial andthe second dial are housed in the casing to adjust a position of theprojection optical system; a moving direction of the projection opticalsystem according to a rotation of the first dial being approximatelyorthogonal to a moving direction of the projection optical systemaccording to a rotation of the second dial; and rotary directions of thefirst dial and the second dial at parts exposed from the casing beingapproximately correspondent to the directions to which the projectionoptical system is moved.
 2. The projector according to claim 1, theprojection optical system position adjuster having a base fixed on thecasing and provided with a hole where the projection optical system ismoved; a mount slidably provided on the base with the projection opticalsystem attached thereto; a first transmitter that transmits the rotationof the first dial to the mount to linearly drive the mount; and a secondtransmitter that transmits the rotation of the second dial to the mountto linearly drive the mount.
 3. The projector according to claim 2, thefirst and the second transmitters respectively having a slider fixed onthe mount to slide together with the mount, and a gear that rotatesalong with the rotation of the first dial or the second dial and mesheswith the slider.
 4. The projector according to claim 1, the projectionoptical system position adjuster including a recognizer for recognizinga reference position of the projection optical system, and therecognizer changing each rotation torque of the first dial and thesecond dial.
 5. The projector according to claim 4, the projectionoptical system position adjuster having a base fixed on the casing andprovided with a hole where the projection optical system is moved; amount slidably provided on the base with the projection optical systemattached thereto; a first transmitter that transmits a rotation of thefirst dial to the mount to linearly drive the mount; and a secondtransmitter that transmits a rotation of the second dial to the mount tolinearly drive the mount, the recognizer including the transmitterhaving a recess or a protrusion, and a biasing member having aprotrusion or a recess and abutting on the transmitter by being biasedtoward the transmitter, and each rotation torque of the first dial andthe second dial being changed when the recess engages with theprotrusion.
 6. The projector according to claim 4, the projectionoptical system position adjuster having a base fixed on the casing andprovided with a hole where the projection optical system is moved and amount slidably provided on the base with the projection optical systemattached thereto, the first dial and the second dial respectivelyincluding a dial body exposed from the casing and a shaft provided atthe dial and fixed on the base, the recognizer including the shafthaving a recess or a protrusion, and a biasing member having aprotrusion or a recess and abutting on the shaft by being biased towardthe shaft, and each rotation torque of the first dial and the seconddial being changed when the recess engages with the protrusion.
 7. Theprojector according to claim 4, the reference position of the projectionoptical system being approximately at a mid position in the movingdirection of the projection optical system.
 8. A projector, comprising:a light source; an optical modulator that forms an optical image bymodulating a light beam irradiated by the light source in accordancewith image information; a device body having a projection optical systemthat projects the optical image formed by the optical modulator in anenlarged manner; and a casing in which the device body is housed, theprojection optical system being provided with a projection opticalsystem position adjuster that adjusts a position of a projection area,the casing having an opening through which the projection optical systemis exposed and moved by the projection optical system position adjuster,a light shield for closing a gap between the projection optical systemand the opening being disposed inside the casing, and the light shieldincluding a ring held at a periphery of the projection optical system ina loosely fitted manner, and an elastic member disposed to extendbetween the ring and a peripheral edge of the opening of the casing. 9.The projector according to claim 8, the projection optical systemposition adjuster having a base having a hole through which theprojection optical system is inserted and moved, and a second lightshield including an elastic member disposed to extend between theperiphery of the projection optical system and a peripheral edge of ahole of the base.
 10. The projector according to claim 8, the elasticmember including a deformable part disposed between the ring and theperipheral edge of the opening of the casing, or between the peripheryof the projection optical system and the peripheral edge of a hole ofthe base, and attachments provided on both ends of the deformable partto be attached to the ring and the peripheral edge of the opening of thecasing, or to be attached to the periphery of the projection opticalsystem and the peripheral edge of the hole of the base, and thedeformable part being formed thinner than the attachment.
 11. Theprojector according to claim 8, the light shield including a fixingplate for fixing the elastic member at the peripheral edge of theopening of the casing, and the elastic member being sandwiched betweenthe fixing plate and the peripheral edge of the opening of the casing.12. The projector according to claim 8, further comprising: a projectionoptical system position adjuster that moves the projection opticalsystem on a plane orthogonal to a light-projecting direction and adjustsa position of a projection area, the projection optical system positionadjuster having a dial exposed from the casing when the dial is housedin the casing, a position of the projection optical system beingadjusted according to a rotation of the dial, and a rotary direction ofthe dial at the part exposed from the casing being approximatelyconsistent with a direction to which the projection optical system ismoved.
 13. The projector according to claim 12, the projection opticalsystem position adjuster having a base fixed on the casing and providedwith a hole where the projection optical system is moved; a mountslidably provided on the base with the projection optical systemattached thereto; and a transmitter that transmits a rotation of thedial to the mount to linearly drive the mount.
 14. The projectoraccording to claim 13, the transmitter having a slider fixed on themount to slide together with the mount, and a gear that rotates alongwith the rotation of the dial and meshes with the slider.
 15. Theprojector according to claim 12, the projection optical system positionadjuster including a recognizer to recognize a reference position of theprojection optical system, and the recognizer changing a rotation torqueof the dial.
 16. The projector according to claim 15, the projectionoptical system position adjuster having a base fixed on the casing andprovided with a hole where the projection optical system is moved; amount slidably provided on the base with the projection optical systemattached thereto; and a transmitter that transmits a rotation of thedial to the mount to linearly drive the mount, the recognizer having thetransmitter having a recess or a protrusion, and a biasing member havinga protrusion or a recess and abutting on the transmitter by being biasedtoward the transmitter, and the rotation torque of the dial beingchanged when the recess engages with the protrusion.
 17. The projectoraccording to claim 15, the projection optical system position adjusterhaving a base fixed on the casing and provided with a hole where theprojection optical system is moved; and a mount slidably provided on thebase with the projection optical system attached thereto, the dialincluding a dial body exposed from the casing and a shaft provided atthe dial and fixed on the base, the recognizer having the shaft having arecess or a protrusion, and a biasing member having a protrusion or arecess and abutting on the shaft by being biased toward the shaft, andthe rotation torque of the dial being changed when the recess engageswith the protrusion.
 18. The projector according to claim 15, thereference position of the projection optical system being approximatelyat a mid position in the moving direction of the projection opticalsystem.